Connect Tech BlueStorm Multi-port Serial Adapter - Manual (Page 9)

BlueStorm/LP Installation Guide, Connect Tech Inc.
Revision 0.05 9
Jumper Configuration
In the following example, the four RS-422/485 ports are set as follows: port 1 is set for half
duplex, port 2 is set for half duplex; port 3 is set for full duplex, and port 4 is set for multi-drop
slave.
Figure 4: Jumper configuration example for 4 port RS-232/422/485 models
TxD Control
Install this jumper to enable the RS-485 transmitter only when sending data. This mode is useful
for half-duplex operation when only one device is allowed to send data at a time. If the jumper is
not installed, the transmitter will always drive the line to an idle state when not sending data.
RxD control
Install this jumper to enable the RS-485 receiver only when NOT transmitting data. This is
useful for half-duplex operation to prevent the transmitting device from receiving its own data as
it sends. If this jumper is not installed, the receiver is always enabled and ready to receive data.
RxD ± Termination/Bias
Install this pair of jumpers to enable a 150 ohm terminator across the RxD+ and RxD- pins for
the corresponding port. A biasing network is also enabled that drives the receiver to an inactive
or safe mode. The receiver can still receive data from another device and the biasing helps to
prevent the reception of data generated by noise on the transmission line. The two jumpers for
RxD termination/bias must be installed and removed as a pair.
TxD ± Termination
Install this jumper to enable a 150 ohm resistor across the TxD+ and TxD- pins of the
corresponding port.
Auto 485 (2 port RS-422/485 models only):
Install this jumper to tri-state the RS-485 transmitters when the computer boots or is reset. Note
that this jumper can be overridden by driver/software with RS-485 support. For example, the
RS-485 modes in the Windows control panel will take precedence over this jumper.
Note also that Auto 485 is a single jumper. The second site is not in use. See
Figure 1 for the
location of this jumper.
Half Duplex and Multi-drop Slave modes require you to select the appropriate
mode via software. Please refer to the readme.txt files found in the appropriate
directories on the BlueStorm/LP CD.
JD1
JD2
JD3
JD4
JD5
JA
JD1
JD2
JD3
JD4
JD5
JB
Port 1 Port 2
JD1
JD2
JD3
JD4
JD5
JC
Port 3
JD1
JD2
JD3
JD4
JD5
JD
Port 4
TxD control
RxD control
RxD
± Termination/Bias
RxD ± Termination/Bias
TxD ± Termination